Commutator exciters which are used to provide a DC current signal to rotors of synchronous generators are still widely used today. Most of these commutator exciters have been installed before 1960 and most of them have not been restored yet. In fact, according to Canadian Electronics Association (ACE) statistics of 2002, 10% of the group's downtime is caused by excitation systems.
An increase in the number of failures of the commutator exciters is therefore expected soon due to the growing age of the commutator exciters. In fact, the downtime generates a loss of earning of about 15 k$/year/machine.
Furthermore, it has been contemplated that the failures are also due to brushes, brush holders and field breakers. Maintenance to avoid such failures amounts about 15 k$/year/machine.
There is a need for a method and apparatus that will overcome at least one of the above-identified drawbacks.